American Museum of Natural History Photo 2018-05-15 19:15

It’s time for Trilobite Tuesday! Even very early on in their swim through evolutionary time, trilobites were an amazingly diverse class. In fact, soon after their emergence in the Cambrian seas, the number of trilobite species numbered in the thousands. One of the more unusual members of this early trilobite radiation was Bolbolenellus, found in the 520-million-year-old rocks of Nevada–and notable for the bulbous shape of its nose-like glabella, which has been somewhat compressed in this attractive 3-cm specimen.